Aircraft control system for control surfaces and wheel brakes



Dec. 28, 1948. E. B. TODD 7 2,457,508

AIRCRAFT CONTROL SYSTEM FOR CQNTROL SURFACES AND WHEEL BRAKES- Filed July 9, 1945 4 Sheets-Sheet 1 {yaw Ber-raid 73dd- My a Attorneys Dec. 28, 1948. E. B. TODD 2,457,508

' AIRCRAFT CONTROL SYSTEM FOR CONTROL SURFACES'AND WHEEL BRAKES I Filed July 3, 1945 4 Sheets-Sheet 2 Inventor Y j V Ed e:- BerJzarcl 15607 B) fizma afih E. B. TODD AIRCRAFT CONTROL SYSTEM FOR CONTROL SURFACES AND WHEEL BRAKES Filed July 9, 1945 4 Sheets-Sheet 3 fin/enter -Eefiyzr Bernard Edd Auntie Dec. 28, 1948. E. B. TODD 2,457,508

. AIRCRAFT CONTROL SYSTEM FOR CONTROL SURFACES AND WHEEL BRAKES Filed July 9, 1945 4 Sheets-Sheet 4 Patented Dec. 28, 1948 Amosrr QQNT M-r a- C N- TROL SURFACE-S AND WHEEI: BRAKES Ed ar-Be nard; T lings. Monti Application July 9,1945, Serial 1330; coast r Mil- 0.)

This invention relates to improvements in aircraft, and more particularly to av control system for aircraft.

The principal objectof; the invention is; to-

simplify the control of an airplane both while on the ground and while in fiight Another object; is to adaptsuch; controls-to any conventional type of" aircraft, suchas those employing a rudder, an elevator, ai1erons, and' lan d'- ing wheels.

The above and other objects may be obtained by employing this invention which embodies among its features an airplane having apair of landing wheels, a tail wheel of the caster-type, abrake for each landing wheel adapted to be actuated independently of that on the other landing wheel, means actuated by a control wheel for operating the rudder, the ailerons; and the elevator of the airplane, means connectedto the control-wheel for operating the-brakes on the land'- ing wheels coincidentally with the operation of the rudder, means associated with the control: wheel for locking the tail caster wheel when the control wheel is moved into position for land ing, and: means whereby the brake-actuating. mechanism is rendered ineffective when the aircraft is in flight.

Other features includea spring-pressed lat-ch bolt. which isadapted to be projected into lockin position by moving the elevators .to landing posi-.. tion, and automatically to be released when the elevators are moved to lifting position.

Still other features embody means. connected: to and, actuated by the aircraft throttle lever for disengaging the brake-actuating; mechanism when; the throttle lever is moved into flying posi: tion.

In the drawings :,v

Figure 1 is a perspective view; of an aircraft q p w th his pa c l r o trol y tem,

Figure 2 isafront; view in; elevation of; Figure- 1,

ure- 3 is a fragmentary side view of; th e r end or tail of the aircraft,

Figure 4 is an enlarged detail sectional view of the rudder control mechanism,

Figure 5 isa diagrammatic view-of the steering or control wheel, its pedestal andthe .contrel cable connected thereto,;

Figure 6- is a side view of Figure 5,

Figure '7 is an enlarged detail plan view of the caster wheel and its control mechanism,

Figure 8 isa longitudinal sectional view taken on the line 88 of Figure '7.

Referring to the-drawings in detail, and aircraft-designated generally comprisesthe-ufiua fuselage i6; to. the" forward end of which are at-.; tached the customary winged-.12 and 18. Each win isrovided adjacent its outer end withtheusual: aileron t9: and secured to the rear end? ortail' or. the fuselage I 5 is the usual rudder The tail: or rear end' of the fuselage It:v is also equipped with the usual elevators 2.1, and mounted on suite able brackets- ZZadjacent the forward end; ofthe f-ueslage I6: are landing whee1s2:3,z and 241.

Attached to therear endof the fuselage and; extending rearwardly therefrom is a; bracket having; formed near its rear end anaperture inwhich the caster wheel, to bemorefully here: inafter described, is pivoted. Rotatably mounted onst-uds 21:: projecting upwardly from the topsur;

face of the bracket 25 are guide rollers; zilzwhich are spaced from one, another, as illustrated Fi ure 7', for the reception. ofthe latch bolt carried by the caster wheel, as will; be more fully hereinafter set forth.

The; caster Wheel is; d i a d; g neralv Z and comprises a Wheel mounted-to rotate about an. axle 3 1 a ried; n a f rked o e t e ii-H nd; of which; is providedwith a pivot stud 33;- which isreceived in the-opening 26, as illustrated in Figure 8. A suitable bearing" collar sur rounds-the tu 33 at tsi nct Withthe y e- 2o Secured'tothe pivot 3?; on the upper side of the bra k a rm .34. w ich i pr v d dth a;- onsi lina 1o -3 he o t n o w ich s m mu W (gates-through a bore 36 with the endof the arm; Slidablymounted in the bore 3 5 5. is; a latch bolt 3;! carrying at its. inner end ahead 38, and; xtend n e e th ea 3 and the end; of the .slotnearest the free endof the arm, 2,4, is a compression coil spring .39 which, asshown, normally; holds the latch bolt in retractedposi: tion. Carried at the-outer end of the latcnbolt, adjacent: the free end of the arm 3 4,,is a yoke 4,!) between the arms of which extends across-pin M to form an anchor for one end; of a cabled}, which, leads forwardly within the fuselage L6,- to the control mechanism tobe more fully herein.-. after described.

Mounted to swing about a horizontalpi-vot $1111 stantially; in alignment with the longitudinalaxis o th f s laee Isi a v r a ja en p os te ends of which are attached-cables 4:4; and 45}; 1) which-leadrearwardly to the oppositeterm nal of a control lever 45 which is connected to. and; dap ed. for on o linge e evat s 1.. A cable 4:!- leads from thelower .end .ofthe lever 43, and is connected by means of a yielding connectionasa; spring 48: to the-cable lz previouslgy described. .Jlt will then-be seen-the r- 43 is moved to cause the elevators to lift the plane, the latch bolt 37 will be moved forwardly, in the dotted line position illustrated in Figure 7, between the rollers 28 so as to lock the wheel 30 against pivotal movement about the axis and pivot 33. In this way the caster wheel 30 is held in a straight-away position so as to not interfere With the proper take-off of the plane.

Mounted to pivot about a horizontal axis adjacent the forward end of the fuselage l 18 a pedestal 49 carrying at its upper end a bearing 50 in which a shaft 5| is rotatably mounted. Projecting downwardly below the horizontal axis about which the pedestal 49 is pivoted and formed integrally with said pedestal 49 is an arm 52 to the lower end of which is pivoted one end of a link 53, the opposite end of which is pivoted, as at 54, to the lever 43 previousl described. It will thus be seen that as the pedestal 49 is swung about its horizontal pivot, the lever 43 will like wise be moved to govern the movement of the elevators 2!. Attached to the pedestal-49 intermediate its ends is a pair of oppositely extending arms 55 carying at their extreme outer ends guide rollers 56 over which cables 51 and 58 are adapted torun. The upper end of each cable 57 is connected to 'a sprocket chain 59 which runs over and engages a sprocket 6B fixed to the shaft 5!, on one side of the bearing 55. Carried by the shaft 5! on the opposite side of the bearing is a control wheel El, and it will thus be seen that as the control wheel is rotated, pull on one or the other of the cables 58 will be exercised. The end of the cable 57 opposite that which is connected to the sprocket chain 59 is connectedthrough the medium of a spring 62 to one end of an equalizing bar 63. The opposite end of this equalizingbar is connected through the medium of a spring 64 to the end of the cable 58 opposite that which is attached to the sprocket chain 59. It will thus be seen that as the wheel BI is rotated, the equalizing bar 63 will be moved.

As illustrated in Figure 2, each of the wheels 23 and 24 is provided with a suitable brake mechanism, each carrying a lever 65, by means of whichits application to its respective wheel may be governed. Leading from the equalizing bar 63 near the end of which a spring 62 is attached is a cable 66 and a similar cable 61 leads from the bar 62 near the end to which the spring 64 is connected. The cable 51 is led over suitable guide pulleys to the lever 65 controlling the brake mechanism which is associated With landing wheel 23, while the cable 66 leads over suitable guide pulleys to the lever 65 controlling the brake actuating mechanism for wheel 24. It will thus be seen that as the control wheel (ii is rotated, one or the other of the levers 65 will be actuated to control the application of braking power to one or the other of the wheels 23 or 24. In this manner the direction in which the plane or aircraft travels when grounded may be governed by manipulation of the wheel 6i.

As in conventional aircraft, I provide a throttle lever 68 by means of which the speed and power of the engine with which the aircraft is equipped may be governed. To my throttle lever 68 levers 14 which are arranged to swing about fixed pivots 15. The opposite arm of each bell crank lever 14 carries a yoke "16 between the arms of which is pivoted a guide roller 11. These guide rollers are arranged in such a manner as to engage the cables 66 and 61 and exert tension thereon through the medium of the bar 63 and the springs 62 and 64 when the throttle lever 68 is moved to taxi or parked position. When the throttle lever is moved to flying position, however, the tension on the cable i0 is relaxed so as to permit the springs 64 and 62 to contract with the result that while the aircraft is in flight, little braking effect is exerted on wheels 23 and 24; likewise, when the aircraft is landing and taxiing about, the brakes of the wheels 23 and 24 are rendered less effective. Not only do I provide for the automatic regulation of the braking power on llh 'Wh861S 23 and 24, but I provide a second lever 78 by means of which the arm 69 may be manipulated to relax the tension on the cable 10 under manual control and independently of the throttle lever 68.

In order to effect proper steering and balance of the aircraft when infiight, I provide on the shaft 5| adjacent the sprocket 65 a second sprocket 19 over which a suitable sprocket chain 80 is trained. Opposite ends of the chain 8ll are connected by cables 8i and 82 to the ailerons carried by thewings I8 and I1, respectively. It will thus be seen that as the Wheel BI is rotated, the ailerons will be moved to proper position to preserve the desired balance of the aircraft when in flight. I. I p f I A control cam 83 is attached to the shaft 5| for rotation in unison with sprockets 60 and T9 for actuating the vacuum rudder control, to bemore fully hereinafter described, in unison with the movement of the ailerons and the application of the brake. Mounted on opposite sides of the shaft 5! is a pair of cylinders 84 and 85, respectively. Leading from the closed ends of the cylinders are tubular connections 86 and al, respectively, by means of which communication is established with valves 88'and 89, which, in turn,

are connected through chambers 90 and! with a manifold 92 which, in turn, is connected through a branch 93 with the intake manifold of the engine with which the aircraft is powered. It will thus be seen that a vacuum is established ated. The valves'BB and 89 are provided with L-shaped valve stems 94 which are pivoted, as at 95, to the cylinders 84 and 85 in such a manner as to be engaged by the cam 83 as the shaft 5| is rotated. A piston 96 is adapted to operate within the cylinder 84 and. a similar piston 91 operates within the cylinder 85. The piston rods of the respective pistons are connected through cables 98 and 99, respectively, to opposite ends of a lever I00 by means of which-the rudder 20 is moved about its vertical pivot. It will thus be seen that as one or the other of the cylinders 84 or 85 is evacuated, one or the other of the pistons or 9'! will be moved inwardly to exert pull on one or the other of the cables 98 or99, andconsequently move the rud:

der to effect the steering of the aircraft when it is in flight. It is to be understood, of course, that where the vacuum rudder or steering equipment is employed as an auxiliary tothe conventional steering equipment of an airplane, a'suitable manually controlled valve may be interposed in the vacuum line 93 by which the mechanism just described may be rendered inoperative.

It will be appreciated that the proper ratio be tween the sprockets 60 8411119, and the cam or eccentric 83 is to be preserved to effect proper coordination of all component parts of the steering equipment of the aircraft.

From the foregoing it will be seen that the operation of the rudder 20 is rendered coincidental with the operation of the ailerons and when the aircraft is grounded and being parked, the rudder and brakes on the wheels 23 and 24 likewise are coincidental in operation. It will also be apparent that as soon as the throttle control lever is moved to flying position, less braking effect is transmitted to the brakes on the wheels 23 and 24 by the movement of the control wheel 6|. It is also evident that the movement of the pedestal 49 about its horizontal pivot not only governs the movement of the elevators 2i, but also controls the looking or releasing of the caster wheel 30 to insure its remaining in proper position for landing and yet may be readily freed for turning about its pivot after the aircraft has been safely grounded and to facilitate its maneuvering when resting on its landing wheels.

While in the foregoing there has been shown and described the preferred embodiment of this invention, it is to be understood that minor changes in the details of construction, combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as claimed.

I claim:

1. Aircraft which includes a pair of spaced landing wheels for supporting the forward end of the aircraft when it is grounded, a caster wheel for supporting the tail of the aircraft when it is grounded, common means selectively to control the speed of rotation of each landing wheel for steering the aircraft when it is grounded, means connected to the common means for steering the aircraft While it is in flight a throttle lever for regulating the power output of the aircraft power unit and means actuated by the throttle lever to render the common means inoperative relative to the landing wheels when the throttle lever is moved to flying position.

2. Aircraft which includes a rudder for steering the aircraft while it is in flight, ailerons adapted to cooperate with the rudder when the aircraft is in flight, a pair of spaced landing Wheels for supporting the forward end of the aircraft when it is grounded, means for retarding the rotation of one or the other of the landing wheels coincident with the operation of the rudder and the ailerons, a throttle lever to regulate the power output of the power unit of the aircraft, and means actuated by the throttle lever to disengage the wheel-retarding means when the throttle is moved to flying position.

3. Aircraft which includes a rudder for steering the aircraft while it is in flight, ailerons adapted to cooperate with the rudder when the aircraft is in flight, a pair of spaced landing wheels for supporting the forward end of the aircraft when it is grounded, a throttle lever for regulating the speed of operation of the aircraft power unit, brake means for retarding the rotation of one or the other of the landing wheels when the aircraft is grounded, and means operated by the throttle lever for releasing the brake means when the throttle lever is moved to flying position.

4. Aircraft which includes a rudder for steering the aircraft while it is in flight, ailerons adapted to cooperate with the rudder when the aircraft is in flight, a pair of spaced landing wheels for supporting the forward end of the aircraft when it is grounded, a throttle lever for regulating the speed of operation of the aircraft power unit, a brake for each landing wheel, means for applying one or the other of the brakes coincident with the operation of the rudder and ailerons, and means operated by the throttle lever partially to release the brake-applying means when the throttle lever is moved to flying position.

5. Aircraft which includes a rudder for steering the aircraft while it is in flight, ailerons adapted to cooperate with the rudder when the aircraft is in flight, a pair of spaced landing wheels for supporting the forward end of the aircraft when it is grounded, a steering wheel, cables controlled by the movements of the steering wheel to control the rudder, cables actuated by the wheel to move the ailerons coincident to the movements of the rudder, cables actuated by the steering wheel to retard the rotation of one or the other of said landing wheels coincident with the movements of the rudder, a throttle lever to regulate the speed of movement of the aircraft, and means actuated by the throttle lever to release the tension on the cables governing the wheel rotationretarding means when the throttle lever is moved to flying position.

6. Aircraft which includes a rudder for steering the aircraft while it is in flight, ailerons adapted to cooperate with the rudder when the aircraft is in flight, a pair of spaced landing wheels for supporting the forward end of the aircraft when it is grounded, a steering wheel, cables controlled by the movements of the steering Wheel to control the rudder, cables actuated by the wheel to move the ailerons coincident to the movements of the rudder, cables actuated by the steering wheel to retard the rotation of one or the other of said landing wheels coincident with the movements of the rudder, means to release the tension on the cables governing the wheel rotation-retarding means when the aircraft is in flight, a throttle lever for regulating the speed of operation of the aircraft power unit, and means actuated by the throttle lever for releasing the tension on the brake-actuating cables when the throttle lever is moved to flying position.

EDGAR BERNARD TODD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,662,306 Fokker Mar. 13, 1928 2,074,730 Kerr Mar. 23, 193'? 2,340,237 Upson Jan. 25, 1944 2,355,026 Koppen Aug. 1, 1944 Re. 22,674 Noonan Sept. 18, 1945 

